by Jarrett Bell, USA TODAY Sports

by Jarrett Bell, USA TODAY Sports

DETROIT ‚?? Johnny Manziel was all smiles when Kyle Shanahan stopped by his stall in the visitor's locker room at Ford Field on Saturday night for a quick chat.

That Manziel still had a bounce in his step as he headed to the buses was a good sign, too.

Manziel made his NFL preseason debut against a cast composed primarily of Detroit Lions backups, and he survived. During a quarter-and-a-half of work after relieving Brian Hoyer, he looked like he belonged on an NFL stage. Even added a spark.

Yet the same element of Johnny Football that undoubtedly excites the long-suffering Cleveland Browns fans is the same element that will make them worry.

Johnny Football can make a split-second decision in a hurry, and make something happen.

That was evident on his signature play of the night. On a fourth-and-1 from the Detroit 29, Manziel, listed at 6-0, 210, took a snap from the I-formation and rolled out to his right. Fullback Ray Agnew was open in the flat, but Manziel's vision was obstructed by onrushing linebacker Kyle Van Noy.

For a brief instant ‚?? like the same time that Agnew was open ‚?? it looked as though Manziel was about to get crushed. But Van Noy couldn't corral him. Manziel slipped and squirmed out of that mess, and after glancing Agnew's way again, decided to keep the football and dash to the sticks.

He got out of bounds with a one-yard gain that moved the chains, but probably ran 25 yards to get there. First down! Johnny Football magic! And at the end, he took a hit.

Maybe as he grows up, Manziel will learn to flip that football fast to his fullback.

Worried about too many hits?

"You always are," Shanahan, the Browns' new offensive coordinator, told USA TODAY Sports as he walked to the buses. "Especially when guys scramble around and try to make those plays. It's a fine line."

Now it's Shanahan's job to collaborate with Manziel and manage this.

Manziel had a few good throws, completing 7 of his 11 passes of the short and intermediate variety. There wasn't much to be seen of his strong arm on the deep throws.

But his footwork was surely on display. Manziel had a team-high 27 yards on six carries. You can only imagine how much he may have run if he had played a full game.

This is not the formula for long-term success as an NFL quarterback.

"Obviously, that's not the plan for me to get that many carries every week," Manziel said. "But at the same time, the more and more I get better at progressions, the more and more I get comfortable with the play-calls and the scheme and what we're trying to do‚?¶hopefully that'll weed down."

Shananhan knows what Manziel means. In his previous job as Washington's coordinator, he crafted the offense that facilitated Robert Griffin III's breakout rookie season.

Griffin was NFL Offensive Rookie of the Year, and he sparked a late-season run to the playoffs.

But Griffin's rookie year ended with a shredded knee, and he hasn't been the same since.

The Browns offense, at least when Manziel was in the game, resembled the RGIII-fueled scheme for Washington in 2012, with the pistol formation and read options. Manziel likes it, as these features constitute a takeoff from the scheme he flourished in at Texas A&M.

"I don't want to put too much pressure on him," Shanahan said. "I want to be able to do something he's comfortable with."

The read-option plays can force the defense to hesitate and adjust, but this must be weighed against the additional risk and hits on the quarterback. To win and survive in the NFL, Manziel ‚?? and Griffin, too, for that matter ‚?? must be able to slice up defenses from the pocket.

You know what they're thinking. If you can do both, even better.

They just can't ignore the risk. On Saturday night, Manziel and Shanahan were upbeat about the quarterback's ability to protect himself and limit exposure. He got out of bounds. He slid to avoid a hit. He was smart about his running, not getting too greedy.

But that was one game, against backups. Whenever Manziel wins the job ‚?? it's a matter of when, not if ‚?? the tests will come against even faster, more powerful defenders.

Strikingly, Manziel's longest run ‚?? 16 yards ‚?? came on a third-and-eight that started with him in the shotgun. After checking maybe a couple of his progression, he bolted from the pocket. And slid safe.

That's what he offers that Hoyer doesn't. He can improvise and make a play.

Yet it was also striking that Hoyer, in his first game since tearing an ACL in early October 2013, said he didn't take a single hit during his one-and-a-half quarters of duty.

On Saturday night, the Browns had distinct game-plans, depending on the quarterback.

"It's give and take," Shanahan said. "You really don't know what people can do until you put them in the game."

Browns coach Mike Pettine has indicated that he will pick his starter before the third preseason game, against the St. Louis Rams on Aug. 23. It seems logical that Manziel will start at Washington on Monday night, but that's officially still up in the air.

"We're still determining it," Shanahan said.

Yet he knows what needs to come next for Manziel.

"Either way," Shanahan said, "he will get him some time with the ones."